[YesAuto Classic Engine Tour] When you talk about feelings, what do you think of? Classic, unique, always remembered and often mentioned and missed. Some of the literature and art are like you who like cars. The first car you saw in your childhood memory. Although it is not perfect, you always think of it. It always has nostalgia, and can not forget it for a long time. You may pay attention to this feeling in every aspect of your life. The so-called feeling of emotion is given to it. Therefore, talking about feelings is bound to be closely related to some people, things and things. Feelings do not come out of thin air. When it becomes a classic and can not be forgotten for a long time, this kind of souvenir will produce sentimental color.
Then again, on what basis does a “sentimental” engine make people remember? Perhaps the answer is not unique, but the originality and adherence to the original intention must be one of the reasons for its feelings. Today we are going to talk about this engine, maybe its performance is not very outstanding, maybe its fuel consumption is amazing, even if you don’t know anything about cars, you don’t even know that there is such an engine. It has been in production for nearly 60 years without ever changing to a large structure. This engine full of British feelings, after more than half a century of production, is about to withdraw from the stage of history. It is the Bentley Rolls-Royce L-Series engine.
If you are a British car fan, if you talk about the famous British engine, then today's protagonist must make you excited. First of all, the production in the past 60 years has been improving without a major change, making it likely to be the engine with the longest production cycle in the world. Secondly, its appearance represents the top engine industry level in the UK, even if it is used now To look at this engine with his eyes, it still has its unique charm, classic and not outdated.
● Change the cylinder layout, the origin of the V-type engine
Engines with this structure first appeared in the early 20th century. That is to say, people discovered this problem shortly after the emergence of multi-cylinder engines. However, because the vehicles at that time did not pursue the extreme space, and in terms of the aesthetics of the year, The long and narrow engine compartment is more elegant, so the V-type engine has not been sought after by people.
The cylinders are arranged in a V shape. Compared with the in-line layout, this approach can make the engine length shorter and reduce the weight of the engine, while the length of the crankshaft can also be shortened. The short crankshaft design not only saves space, but also improves the lack of strength and vibration caused by the excessively long crankshaft. In this way, the V-type engine can improve engine ride comfort and reliability, and is quieter. And only one year later, the predecessor of our protagonist today-the first Rolls-Royce V8 engine was born in 1905.
After that, Rolls-Royce acquired Bentley and began the era of sharing technology with Bentley. Although sharing technology development, I don’t know if it’s “I was bitten by a snake for ten years and I was afraid of well ropes.” Until World War II, there had not been a mass-produced V8 car engine.
Based in part on the structure of the early Rolls-Royce V8 engine, the new engine should be smaller in size, higher output horsepower, lighter weight and quieter engine sound. Based on these concepts, the Rolls-Royce Bentley L series V8 engine, which was developed in 1952, was born.
● The birth of L series engine
As for why the L series engine is great, you will understand through a story in the development process that year: This engine not only has to meet excellent technical standards, excellent durability, and even styling. Perfection. At this time, you may ask, does an engine still need aesthetic beauty? This is Rolls-Royce and Bentley, a brand that the British are proud of. If you don't do this, you are ashamed of the angels and big B marks on the front of the car.
Living up to expectations, this L series engine developed by Rolls-Royce Bentley, when it was officially unveiled in 1959, was much better than the products of the same period in terms of noise control, volume and power output. All technical requirements and harsh design Needs to be surpassed, not only ensured the high power output of the contemporary engines, but also fully optimized the NVH, which was considered an extremely rare development direction at the time.
The early version was a 5.2L naturally aspirated V8 engine named L380. This engine was mainly used for development and testing. Until 1959, the most famous model in the L series engine, the L410, was born.
As the most famous product in the L series, the L410 did meet the original target design requirements: not only the output horsepower surpassed the early Rolls-Royce V8 engine by more than 50%, the engine volume was only the length of the inline 6-cylinder engine, and it was The aluminum cylinder block is used at any cost, which reduces the weight of the engine by more than 13kg. In addition, the flat short crankshaft design and relatively unique ignition sequence of the engine give it excellent ride comfort and noise control. As for what the 410 number represents, I will sell it first, and I will tell you the answer when I explain this classic engine below.
Decades of waiting, 7 years of research and development, in exchange for this L series engine. Perhaps no one expected that due to its reliable structure, excellent power output and smoothness, this engine could influence the Rolls-Royce and Bentley brands for more than half a century. Until now, Bentley Mulsanne still loves this series. engine.
We all know that the calculation of engine displacement is the result of multiplying the cross-sectional area of a single cylinder, piston stroke and the number of cylinders, which is the formula nπ(d/2)²l (n represents the number of cylinders, d represents the bore diameter, and l Represents the itinerary) to get the result. From a single-cylinder perspective, the cylinder diameter and stroke of the early L410 engine were 104.14mm and 91.44mm, respectively. At this time, someone will definitely say: This data is still rounded, not an integer? I see that the bore and stroke data of many engines are integers. Why is this?
So remember what the 410 in L410 mentioned earlier refers to? That's right, these three digits represent the cylinder diameter, from which you can infer the cylinder diameter of the previous L380 5.2L V8 engine: 3.8 inches. The cylinder diameter of an L425 engine that will be mentioned later can also be inferred.
● Engine model and matching models
In the early L410 engines (from the late 50s to the 80s), the 6.25L displacement option was adopted. Most of the classic Rolls-Royce and Bentley models designed by John Blatchleys are equipped with this engine. Of course, the L series engine But not just the L410, many improved engines such as the L410I 6.75L V8, the L425 7.45L V8 engine and the L675 “renamed L410” engine belong to the L series. Below we will focus on the models that are more famous in the L series. Do some introduction to the product.
Also in 1965, the L series engine appeared the “most displacement” in the history of this engine: a 7.45 V8 engine named L425 was born. This engine has indeed created new highs in power and displacement, but due to the fact that this engine has found problems with smoothness and poor noise control during the experimental stage, this engine only appeared in the experimental stage and did not really Mass production. Indeed, for brands like Rolls-Royce and Bentley, poor ride comfort and noise control are enough to make them abandon this engine.
After retaining the original cylinder diameter and increasing the piston stroke, this L410 6.75L V8 engine finally made a “real” optimization for the old L410 engine. Based on this, many engine modifications were developed later, such as in 1982. The L410D that started production is equipped with a turbocharger style and so on. Perhaps for such a luxury car, no matter how powerful the horsepower is, there is rarely a chance to run so fast, but in order to walk elegantly on the street, and have on-call dynamic response to propel such a heavy car, torque Is everything.
Although the 6.75L displacement L410 engine is a classic, it has also become the pride of the British, but the “Bing and Lao division” matter can not avoid disputes over the license for this classic engine in the future. In 1998, the Volkswagen Group acquired Bentley and obtained the production license and right to use the L series engine, but BMW only obtained the right to use the Rolls-Royce trademark, which inevitably made Rolls-Royce in this ” The use of “feelings engine” has created obstacles.
Although it is still familiar with the displacement and structure, for the current Mulsanne, while emphasizing feelings, it is also necessary to upgrade this engine. Through the application of twin-turbo boosting and direct injection technology, coupled with the closed-cylinder technology, this nearly half-a-hundred-year-old L410 engine has been reborn.
The engine model of the current Bentley Mulsanne is called L410HT. Compared with the earliest L410, almost all parts are brand new. The performance of 537Ps and 1100N·m (Bentley Mulsanne 2015 Ultimate Edition) has surpassed the data. More than 150% of the power and torque performance, harmful gas emissions have also been reduced by 99.5%, and fuel economy is also better than the first generation by more than 40%.
Although in the course of half a century of evolution, the L series engine has been continuously optimized, keeping the traditional structure while keeping up with the pace of advanced technology, but the classic does not mean perfect. The half-century of the ancient structure hinders the future performance of this engine. It is inevitable that the optimization and promotion of aspects and emissions will be eliminated by the times. Of course, because the British are obsessed with this engine that is more than half a hundred years old, the L series engine and Chevrolet's LS series engine have become one of the engines with the longest production cycle in the world.
Emphasis on feelings, this engine definitely carries the most lasting feelings of the British automotive industry. From the beginning of perfection to the stacking of various new technologies, the L series engines have been enduring for a long time. After 60 years, the residual temperature will still exist, not losing to the products of the current advanced era. Perhaps it is this obsession with perfectionism that has achieved its myth in the field of engines.